Rotary retracting soot blower construction



Nov. 1, 1949 H. E. BRELSFORD 2,486,585

ROTARY RETRACTING 500T BLOWER CONSTRUCTION 2 Sheets-Sheet 1 Filed Jan.24, 1946 up wpu ,z

FE: IM'ENTOR.

' Nov. 1, 1949 H. E. BRELSFORD ROTARY RETRACTING SOOT BLOWERCONSTRUCTION Filed Jan. 24, 1946 2 Sheets-Sheet 2 Patented Nov. 1, 194.9

ROTARY RETRACTING SOOT BLOWER CONSTRUCTION Harry E. Brelsford,

Birmingham, Micln, assignor to Diamond Power Specialty Corporation,Detroit, Mich., a corporation of Michigan Application January 24, 1946,Serial No. 643,055

12 Claims.

The present invention relates to improvements in soot blowerconstruction.

One of the primary objects of the present invention is to provide animproved soot blower construction which is particularly adapted for usein the hottest part of the furnace and which is so constructed andarranged so as to increase its life.

A further object of the invention is to provide improvements in sootblower constructions of the type mentioned in which the blower isprojected into the furnace only during the blowing operation and isprotected in a retracted position when not operating.

Another object of the invention is to provide improvements in sootblower constructions of the type mentioned which will permit making asecurely sealed joint where the blower enters the furnace wall, therebypreventing leakage of gases from the furnace outward or the leakage ofair from the outside into the furnace.

Another object of the invention is to provide improvements in sootblower constructions of the type mentioned in which the traveling memberis securely held so that all strain against this traveling member isrestrained by means rigidly related and so as to relieve thecommunicating member from all strain.

Another obiect of the invention is to provide improvements in sootblower constructions of the type mentioned in which the traveling memberis restrained until it reaches the desired travel and then is releasedfor any desired number of rotations so that the particular cleaningcycle may be followed.

A further object of the invention is to provide improvements in sootblower constructions of the type mentioncd in which there is provisionfor accessibil ty to the valve without interference to the piping.

'Another object of improvements in the soot blower constructions of thetype mentioned which will permit ready operation of the valves againsthigh pressure through relat vely slight effort on the part of the motivemeans of the blower itself.

Other objects of the invention will become apparent from the followingspecification, the drawings relating thereto, and from the claimshereinafter set forth.

In the drawings, in which like numerals are used to designate like partsin the several views throughout,

Fig. 1 is an end elevational view of a soot blower constructionembodying features of the present invention;

Fig. 2 is a cross-sectional view, with parts in elevation, takensubstantially along the line 2-2 of Fig. 1 and showing the constructionin its relationship to the furnace wall;

the invention is to provide Fig. 3 is a cross-sectional view takensubstantially along the line 3-3 of Fig. 2; and

Fig. 4 is a cross-sectional view taken substantially along the line 4-4of Fig. 2.

It is frequently desirable to place soot blowers on the sides of boilersor furnaces so that they may project into the hottest part of thecombustion space in order to direct the cleaning fluid onto theunderside of the generating tubes, or other parts of the boiler, andwhere the location is so hot that the blower cannot remain in thefurnace but must be retracted as soon as the blowing medium isdiscontinued. There are various types of such blowers, some which havevery long travels, up to twenty feet, and others that require much lesstravel when it is desired only to clean heatin surfaces close to theurnace walls. The present invention is directed to the latter type andhas'a travel of approximately twelve inches forward toward the boilerfrom its retracted position. This is sufiicient to retract the nozzleinto the boiler wall space where it is protected from the heat while itis inoperative and yet allows it to project sufficiently into thecombustion 'space so as to efficiently direct the cleaning fluid ontothe surfaces of the boiler to be cleaned.

Because of the nature of the service, it is desirable that the cleaningfluid b turned on automatically as soon as the nozzle reaches itsmaximum projection and before it becomes appreciably hotter so as toendanger its life. It is therefore necessary that such a head beautomatically valved in order to protect it from the heat. as well asfrom th standpoint of efiiciency in use of the cleaning medium. Such ahead may be either manually or power controlled, and in either case itis desirable that the traversing motion be fairly rapid to conserve timeas well as effort, because when power controlled by a power motor, thespeed is fixed and the time interval of traversing becomes a definite,fixed interval and becomes important where thereare a great many unitson aboiler to be operated in a given time. The construction of thepresent invention thus provides a head with the necessary travel, withthe means for rapidly producing this travel, and of a rugged.construction which permits maintenance of rigidity and relative positionwhile blowing. The construction of the present invention also lendsitself either to manual or power operation.

Also, in general, the construction of the present invention is one whichpermits making a securely sealed joint where the blower enters thefurnace wall and prevents leakage of gases from the furnace outwardly orfrom the outside inwardly. The projecting element has a smooth,uninterrupted exterior which permits of a packed joint to accomplishthis. Furthermore, when fully exnot impose'any strainpIr-thetelsc'opic-arrangement of the two tubes with consequent damage to thepacking which seals the joints between the two tubes. Also, a rigidconstruction-is-provided.i

which takes the reaction forces when the news ing medium is beingdischarged. Furthermore, inasmuch as steam pressuresareccntiiiuahyiricreasing, it is becoming more" andinore'niflicultWPf" to directlyopen a valve under high 'pressure'because of the excessive forcereqniredandnthereaw fore, according to the present invention, a self--opening valve is provided. which is controlled by r a pilot valveoperating thi'ough the medium of an unbalanced piston'w Tli'e blohvingmedium visliiitroduced'to the head structuretransversely of the" valveaxis, ascompared'to" *ax-ia'1ly thereof, and it is, thereforewnotnecessary" tci disturb the piping connections-'tmthis head for accfohregriridirig, or other attentions- Referring *to -th drawings; theblowitnghead is generally-indicated ate-"I and is adafpted- 'to bemounted to the exterior surface of a furnace wall adjacent 'an' openingcommunicating with the zrw in'terio'r thereof, in' th' usual-Way. Thefurnace wal-l (not shown) 'hasan opening therethrough"= whichcommunicates "with' the' combustion space within the furnace, and iii*the' present" instance bears-'to close communication between chambers"I u 4 and'-5."'- VVhenthe valve 9 ism'ovedewayfrom" thevalv'e'seat'8,communication is establ'is'hed'be-.:-- tween'chambe'rs 4and 5.

Valv'e'disk 9 is mounted 'on a stem I 0, and such a pistorrl I by-meansofa 'loclrwasherdz and a lo'ck nut I3 The ldoseness is between theperiph-"- ery'of the" stem I and the "opening throughthe" locknutsothat' there'may be nobinding-in move mentof'the plunger? The locknuti3" is"secured-' against'locsening bymeans'of a locking disk 'I4i I Thestem" Ii] extends througha central aper ture'in disk '9, and' suchvalvedisl:*se'ats" on-"a tapered shoulder-1 5' on the valve rod I0 andisground to a tight'joint on'thshoulden" The in-"- termediate'portion'of thevalve" stem-"is reduced" and "threaded ,-"and-lock nuts-I6 are received on th--threaded=portion adjacent the upper fa'ceofthevalvediskw so that' the valvedisk 9 is' m'oved in either direction-du'e- *to th'e 1 engagement "of" shouldeiwm or the undei lolzk nutIGJ-as the ca's'e may be. The lock nuts may be adjustabl y"positiciied-'-'bn th'e threadedportionso thatany: desiredfidegree offreelininizor' slight ilost motion-- masabe impartedto thetdiskd.J

The 'upper and: reduced:=end-- ofnthe: valve stem? I 93 iisiindicatetl-at I i ancb'is guided in :a .gu-ide bushing. I 8 whichvisithise'aded:thirou'gh'ia threaded. opening .initlre'. castingtcat.theltop rm-chamber. 4 imzaxiai:.ialtgnmentiwithzithez.vahientstemc. Thea Alaterally'extending A throttling diSkZB is threa'dably mounted on"-guide bushing I8 is vented as indicated at I9 soas-itoprevent.compression'ofth.blolwirigimedium izi'thespace betweenthe-er-id-of the valve stem and the end of the guide passage.

Piston I I is reciprocably mounted within a bore 20....formedimthe-casting 3 and communicating thr'oughfthe' lower side with chamber5. An end plate 22 is bolted to the lower end of the casting adj'acenttli'e=bore -:2IIby means of bolts 23. The pistdr1I I is'zforcedfiipwardly, or to its valvecldsing positib'n,b$ means of acompression spring 24 Sofia/S1130 seatlthezvalve disk 9 against itsvalve seat. A stop rod 25 is mounted centrally on the endpla'tefiz andprojects upwardly within the bore 29 so as to limit thedownward movementof th= piston- I I, togetheiewvithithex'operatingz' parts connectedthereto. Theiipistom'l I1 isznot azpenrfectly tight fit withinith'etbore;:itibeing.:intended that'thre'would besome' leakagefpastithispiston".- into th'e' bore 207 sori'lha'tuthere will. .be equalization-noffluid pressure between' chamber?!) and flth'eie chamber formed by"bore- 291 The particularaz: function of this will be more apparentfromua later de'scrintiom the bushing I8 within the chamber 4 'and adjacent the top edgecf valve member'B. B37- adjustingthe orifice disk-' 25-on *the member HiQ- any desired clearance between itself and theexitsid'eofth'e valve seat 8 may "b'provideii so' astogive the desiredthrottling of the --'blowin'gmedium when "pressure on the discharge?side of-the valve isto be less thanthesupply pressure. The -pe'-"--riphery of the disk26 is fo'rm'ed'withdepressions at spaced'intervalstherearoundjandit maybe secured in any positionby'means of'a stopscrew"2'! (Fig. '1)' .whichextendsiwith'in chamberfl and the end of whichprojects .with'inone of 'the I depressions in the peripher-yof thedisk'26'j The casting 3 "is' formed with cleaning fluid"? passageway28,the end of whichis'in' open communication with chamber 4. The outletendcom municatesthrough a horizontal opening 29 'foi'med in afla'ngeportion 3D"of.thecasting-= A. bracket. 3 l=- isconnected to the.opposite. end of thecastingby means ofcap screws 32 and .ter-f minatesin upwardly-.- extending and laterally: spacedprojecting,portions. .33and. 34'.-'

The entire blowing unit I is mountedntorthea exterior surface/0f thefurnace -wallagainstw-the usual wall. box fitting by bolts extendingthrough the-flange ofuportion 34a 7 I In-general,- the projecting meansinclu'des a a pair of telescoping members, the exteriorione of which hasa blowing. nozzle-I 35- connected-t0. the

end thereof. Such telescoping-members: are indi-icated-at--36 andB'IaMember-:35Fis'a tubul-an meme'sber;.-circularr in-rcross-zsection', andhavinga thread: 38 X formed x'on' the outsidewsurfa'ce intermediate fthe ends thereof. Theleft-handend'ofrmemberr -3 6' is received withinopening :3 9 formed in'rfiange 39,*and packingdmis disposed be'tweenntheouter. surface of member 36' and the inner: surfaoemfi" opening 39. Thetube 36 is secured' agalnst-axiai movement-by-means-oft a thrustbearing. II-.1 The thrust bearing 4 I? is mounted beiazveen-"aflangedmember 42, which is secured to flange 39*bymean'sq of bolts? 43,and-ran annularzmemberr 44. The

fiangemember. 42 hasan inwardly-extending an nular flange 45 whichengages the outercsuriace ofrthe outerbearingracer: Memberi- 44 hasfianaxially directed 'annularfiange 46 which engages. the. adjacent face oftherinneribearingrace. Then inner end of packingll lflrabuts .againstiabearing:

shoulder in casting 3 adjacent opening 29. The

opposite end of the packing abuts against a shoulder flange on member 44which is telescopically received within opening 39 of flange portion 30.

A driving member 48, in the form of a pulley in the embodimentillustrated, has a hub portion 49 within which the tubular member 38 isreceived. Such member 48 is secured to the member 36 by means of screws50, so that the member 36 rotates with the driving means 48. Thelefthand end of the hub portion 49 telescopically receives thereon thebearing races of the thrust bearing 4|. The outer bearing race abuttingagainst a shoulder formed on the hub 49, and the inner bearing race issecured in place by means of a snap ring 5|. Since tubular member 36 isfixed to member 48, which in turn has the thrust bearing axially fixedwith respect thereto, and since the flange 45 of the member 42 axiallyfixes the thrust bearing to the flange 30 of casting 3, it will beevident that the member 36 is held against axial movement, but mayrotate with respect to casting '3. p

The right-hand end of the tubular member 36 is supported within thetelescoping member 31. Such end of member 36 is reduced and has apacking 52 embracing the reduced end and held in place by bearing rings53 and 54. Bearing ring 53 abuts against an adjacent shoulder formed inmember 36, and ring 54 is held in place by means of a snap ring 55.Axial and rotative relative movement between members 36 and 31 is thuspermitted.

Member 31 is circular in cross section and has a smooth, uninterrupted,exterior surface. It projects through an opening 56 formed in bracketportion 33 and also projects through an axial opening in bracket portion34. The end of member 31 is threaded and has the nozzle 35 threadedthereto. The member 31 is adapted to be moved within the furnace to itsprojected position and retracted therefrom, to the position shown inFig. 2, so that the nozzle 35 is disposed within the opening in thefurnace wall when the blower is not operating. The right-hand end ofmember 31 is guided by means of a guide bushing 51 which is mountedwithin flange portion 34.

Sealing means 58 embrace the tubular member 31 and are disposed betweenthe exterior surface of the member 31 and the adjacent wall of theopening through portion 34. The sealing means abut against a shoulderformed on an inwardly directed annular flange 59, and the opposite endof the packing is held in proper position by means of a packing glandfollower 66. Gases from the furnace, therefore, cannot escape past thepacking 58, nor can air enter the furnace from the outside past packing58, while the member 31 is free to be moved to and from its projectedand retracted positions.

The opposite, or left-hand, end of member 31 is fixed to the hub of anactuating member 6|, as by a weld 62, for example. The actuating member6| has a disk portion 63 and a hub portion within which the tubularmember 31 is received. The hub portion also has an annular, finishedportion 64 which is adapted to be received within opening 56 and bearagainst bushing 65, within opening 56, when the tubular member 31 isextended to its projected position. Since portions 33 and 34 are spacedfrom each other, it will, therefore, be appreciated that when thetubular member 31 is extended to its projected position, it is supportedwithin spaced bearings so that the projecting end of the nozzle isrigidly supported and does not cause undesirable loads on the operatingmeans. I

The actuating member 6| has an annular member 66 fixed thereto by meansof screws 61, and

such member 66 has a projection 68 formed on the inner surface thereofwhich is received within the thread '38 and provides a follower nut tocause axial movement of the member 31 when member 36 is rotated.

The member31 is restrained against rotative movement until it reachesits full, extended position, "at which time it is released so that itmay rotate to effect the blowing operation. This is accomplished throughthe interrelationship between disk member 63 and a pivotally mounted bar69. The disk 63 has a notch 10 formed in the periphery thereof which isadapted to receive the rod 69 therein. When the rod 69 isengaged withinthe notch 19 and the rod is held against movement, the disk 63 cannotrotate, as one of the walls of the notch will abut against the rod 69.The rod 69 extends axially of tube 31 so that the tube 31 and member 6|may move axially, even though they cannot rotate until a particularposition is reached.

The rod 69 has depending pivot arms 1| fixed thereto which in turn havepivot openings therethrough. A pivot rod 12 is mounted on upwardlydirected lugs 13 formed in the casting 3 and serves to pivotally mountthe rod 69. The righthand end of rod 12 projects within an alignedopening 14 formed in bracket 3|. The rod 69 is normally urged to itsupper position by means of a spring 15 which is wound around rod 12 andhas one end thereof bearing against the rod 69 and the other end thereoffixed by abutment against the adjacent surface of casting 3. ViewingFig. 3, the spring acts to pivot the rod 69 in a clockwise direction.

The tendency of the action of member 36 as it rotates is to turn thedisc 63 in a clockwise mally projects, the recess being defined byrear-' wardlyextending projections 18. 19 formed integrally upon thestop member. Projection 16 prevents pivotal movement of the bar 69 inthe indicated direction during advancing movement of the nozzle anduntil the projection 18 is moved out of the way by bodily forwardmovement of the stop structure, which movement is induced by the frontface of cam disc 63. The forward end of the rod 69 then swings acrossand lies in facing relation to the adjacent rear end face of theprojection 18 when the rod is pivoted to the position shown in brokenlines in Fig. 3.

The stop 16 is formed with a notch 89 in the lower edge within which thepivot rod 12 is received. This connection between the stop 16 and therod 12 prevents rotative movement of the stop 16, but permits axialmovement thereof along rod 12.

The stop 16 has a sleeve 8| fixed thereto which is slidably receivedwithin an axially-aligned opening 82 formed in bracket 3|. A compressionspring 83 is disposed within the opening 82, and one end of the springabuts against the bottom of the opening and the opposite endabutsagainst a pin 84 which is fixed to member 16. Thus, the spring 83normally urges the stop 16 toward the rear or left (viewing Fig. 2).

The manner in which the stop 16 is moved to 7 tssout-ni-the'way:positin:.'will:.be: described. in. greater detail hereinafter.

The pivoting-of the-r d .69.;and the len h f the.;;t imethat ;,iti$;jh8ld,1 in; its =piyoted1 position cnntrolsrthe:v opening rof'valvey9, and therefore the-introduction: ofthe. cleaning medium through h.nezz einto th imm nse. The pivotin of the nod-r69- controlstheoperation 01 33; pilot valve 85 which is mounted on casting. 3. The.pilot valve is formed; with anv inner T'chamher and a alves atflfi. tadisk'val-ve 81 s d sposed w th n heeval ve chamh nandzisnorma ly urgedtowa d the-se 6wby'meansof. awsprine .8 h al has a, stem-89; whichextends upwardly through a;pacl ed: epening-inthe top of valve, body85,. to a. position under an actuating arm 90. v The valve.8.5.;ia-laterally ofiset. from the axis of the pivot shaft; 12, and. thearm 90. is fixed to the pivot rod 6% so that as the pivot rod pivots, asshown infig. 3,,the, actuating arm- 90 engages the upper end otstem 89,and depresses the stem to open valve 81'. '.The chamberzwithin. thevalve above the -valveseat, .is .vented toe the atmosphere through an,opening 92.. .I'he chamber within the valve body on the underside ofthe; valve 8'l..is connectedthrough, aconduit 93 with an opening 94,through- .end. plate. 22. Opening 94 communicates withthe.chambeigformed by bore under plun er H.-

.The. wheel 48. maybe turned either yhand. or. it. may, bemotor-drive...I m y einthe form 0t apl ll yvor a chain. spro ket so .that .it m ybe turnedby. hand- .In the pperation of he devi e. assumin h th membeLtoe therwi h the n zzl is n t retracted. p si i n. he valve 91 e thecleanngfl anno pas intocharnh 4. a d. gh

passageway .28 into and through the hollow interior of members 36 and3.! and nozzle 35. When the valve 9 is opened it will, ofcourse, beunderstood. that the fluid follows. this path andis discharged throughthe openings in the nozzle head into the furnace and against'thesurfaces to. be cleaned. "Upon rotationof wheel 48, either, by hand ormotor, the member 36, is also rotated. Therelationship between thread38' and nut 68 will cause the nut; together with members 6L and 37, ttravel axially of member 36 toward the projected position. At this time,the stop 16 is in its restraining-position shown in Fig. 2, so that therod' 69 cannotpivot', andsuch rod is received within the notch-10 withone wall of the notch bearing thereagainst. This continues until thedisc 63 reaches the position to abut against the facing side of stop 76.Continued axial movement of member 31, together with member'fil, causesthedisc 63 to force the stop T6to the right against spring 83. It isforced to that position until the end of-rod 69 is released fromabutment against the one side of recess 71 and is free from projectionl8. As soon asthe rod-'69 is freed so that it may pivot disc' .63. isalso free to turn and during the-initial portion of=itsrotary movement.will cause'rodw69. to pivot aboutits pivot pin 12, as shown in Fig. 3,and cause depression of valverstem 89..so.- as: to vent. valve. 85. to,the atmosphere. *The underside of piston l I is at the same time ventedto atmosphere through opening- 94andconduita93. As mentioned above, assoon as the pressureiunder piston H is vented to theatmosphere,thezfluid pressure within chamber 5-from the/cleaning mediumwill.instantly move' thaplunger downwardly: to open valve 9 and permit thepassage. of: the :cleaningfluid into chamber- 4, passageway 28,-.anditoithe; cleaning nozzle-rthrough-members 1'36 and-31. The cleaning nozzlethereafter rotates. with: member; 31in re sponse tocontinued: turning ofwheel 48 while the cleaning medium is passing through theopeningstherethrough. The valve '85. will be held vented to atmosphereand the unnotched periphery- .ofdisc '63 r-ides.over the rod 69',holding it in its.inclined pilotevalve actuating position until notch?Ill-againreaches-a position so that the spring 15..may.return the rod toits upper position' withinthenotch. Continued forward rotationofthe disk(in the same directionas the wheel-'48 was turned to project the nozzle)is effective tomaintainbar 69 and arm 99 cocked and valve 8'! openthroughout such part of each such-forward-revolution as bar 69 is out ofcam notch 10-,- and blowing" may thus be continued for any number ofrevolutions, although during each such revolutionblowing steam is onlydischarged while the bar is cooked by the higher parts of 0am disc 53,and is'stopped when the bar is raised intothe notched portion of the camby the spring 15. The time in which the actual blowing takes placedependsupon the length of the cut away or, notched portion *1 0 of thedisc, being shorter as such notch is lengthened peripherally. It isillustrated in the drawings of a very small length, but it may extendaround the periphery of the disk up to, for example,

It will be understood, of course, that the driving member 48 is rotatedat. a. more or less uniform rateand, as soon as the rod 69 is notsupported by the periphery of cam 63, the spring 15 will swing the rodin a counterclockwise.direction on its pivot pin .1 2, as viewed. inFig. 4, or in a clockwise direction from .the broken line to the fullline position asshown in Fig. 3; This movement of the rod. .69 releasesthe pressure. of the actuati s arm .90 from. the valve stem 89, thus.permittingthespring. 8.1,.to. close the pilot valve 85, and thus themain.valve. .9. In this wise, itis seen that the. peripheral length of the.notch 10 determines the rtion, of a revolution of the cam 63duringwhich. blowing fluid is not discharged.

Reversal. ofrotation ofthe member .48 will cause retraction of member'76, togetherwith disk 63. This will permit the, stop 16 to move back tothe Position showndmFig- 2, in which position the rod 69,.cannotpivotafterit has once come back into slot. 10. I Continued rocking of the rod69 in a reverse ,(clockwise) direction past a vertical position,asshownin full lines in Fig. 3, is prevented by-the-projection 19 onstop 16 engaging against the forward arm H, such rocking move ment beingin a counterclockwise direction as illustrated in Fig; 4, whichis a viewtaken looking in a direction opposite to that of Fig. 3. Projection- 19is longer than projection 18 so that it always overlaps the bar 69 andfront arm ll as shown in Fig. 2. Further reverse rocking movement oftherod 6'9-beyond the'vertical position being restrained, it followsthat further rotation of cam 63 is prevented, when .abutted by the wallat thefipposite end,of. notch 70. from the end which serves to initiallycockthe bar. Thereupon, further reverse rotation of the driving member48 causes relative. rotation between the threaded tubeili ,andtheblowerelement 31, which will cause retraction. of. the blower element.Qontinued rotation of, the. wheel 48 in the reversed directionwillefiect movement of member 31 to its. fully retracted position showninFig. 2. When the .valve 8,! .isclosed, the above-mentioned leakae past.pis on twi11.--equa1iz.e.the pressures on both sides thereof so that thespring 24 may act with ease to close valve 9.

What is claimed is:

1. A soot blower construction comprising a housing, means providing afluid inlet chamber within said housing, valve means controlling theflow of fluid through said chamber, a fluid passageway within saidhousing communicating with said chamber, an externally threaded tubularmember mounted on said housing and communicating with said passageway,another tubular member adapted to have a nozzle mounted thereontelescopically embracing said threaded tubular member and mountedthereon for axial and rotative movement with respect thereto so that itmay move to projected and retracted positions, said another tubularmember having a smooth, uninterrupted exterior surface, means connectedto said another tubular mcmber and engaging the thread on said threadedtubular member to effect axial movement of said another tubular memberupon rotation of said threaded tubular member, an actuating memberconnected to said another tubular member for movement therewith, meansto effect rotation of said threaded tubular member, movable meansconnected to said actuating member to restrain rotation of said anothertubular member until it reaches its projected position, means to preventmovement of said movable means until engaged by said actuating memberwhen said movable means is released for movement, and means responsiveto the movement of said movable member to efiect actuation of said valvemeans.

2. A soot blower construction comprising a housing, means providing afluid inlet chamber within said housing, normally closed valve meanscontrolling the flow of fluid through said chamber, a fluid passagewaywithin said housing communicating with said chamber, an externallythreaded tubular member mounted on said housing and communicating withsaid passageway, another tubular member adapted to have a nozzle mountedthereon telescopically embracing said threaded tubular member andmounted thereon for axial and rotative movement with respect thereto sothat it may move to projected and retracted positions, said anothertubular member having a smooth, uninterrupted exterior surface, meansconnected to said another tubular member and engaging the thread on saidthreaded tubular member to eifect axial movement of sa1d another tubularmember upon rotation of said threaded tubular member, a disc memberhaving a notch in the periphery connected to said another tubular memberfor movement therewith, means to efiect rotation of said threadedtubular member, a pivotally mounted bar engageable in said notch andextending longitudinally of said another tubular member to restrainrotation of said another tubular member until it reaches its projectedposition, means to prevent pivotal movement of said bar until engaged bysaid disc member when said bar is released for movement, and meansresponsive to the movement of said tubular member to open said valvemeans.

3. A soot blower construction comprising a housing having a passagewayand a fluid inlet to the passageway, valve means controlling the flow offluid to said passageway, an externally threaded tubular memberrotatably mounted on said housing and communicating internally with saidpassageway, a second tubular member adapted to have a nozzle mountedthereon tele- 10 scopically embracing said threaded tubular member andmounted thereon for axial and rotative movement with respect thereto,said second tubular member having a smooth, uninterrupted exteriorsurface, means connected to said second tubular member and engaging thethread on said threaded tubular member to effect axial movement of saidsecond tubular member upon rotation of said threaded tubular member,means to effect rotation of said threaded tubular member, keying meansto restrain rotation of said second tubular member until it reaches oneend of its travel, including a common keying and valve actuating elementmovable concurrently with said second tubular member, and means foractuating said valve in response to movement of said element.

4. A soot blower construction comprising a housing having a passagewayand a fluid inlet to the passageway, valve means controlling the flow offluid to said passageway, an externally threaded tubular member mountedon said housing and communicating internally with said pas-' sageway, asecond tubular member adapted to have a nozzle mounted thereontelescopically embracing said threaded tubular .member and mountedthereon for axial and rotative movement with respect thereto, saidsecond tubular, member having a smooth, uninterrupted exterior surface,means connected to said second tubular member and engaging the thread onsaid threaded tubular member to effect axial movement of said secondtubular member upon rotation of said threaded tubular member, means toeffect rotation of said threaded tubular member, keying means torestrain rotation of said second tubular member until it reaches one endof its travel, including a common keying and valve actuating elementmovable concurrently with said second tubular member, a longitudinallydisposed key interengageable with respect to said element to hold saidelement and the second tubular member against unwanted rotation duringaxial movement of the latter, latch means normally holding the keyagainst lateral movement but releasable by said element as the secondtubular member reaches the end of its axial movement, and meansresponsive to lateral movement of the key for actuating the valve.

- 5. Means as set forth in claim 4 wherein said element comprises a discsecured to the second tubular member and having keying portions andcamming portions engageable with said key and also having latchactuating portions engageable with said latch means.

6. Means as set forth in claim 4 wherein said element comprises a discsecured to the second tubular member and having peripheral keyingportions and camming portions engageable with said key and also havinglatch actuating end face portions engageable with said latch means.

'7. A soot blower construction comprising a housing having a passagewaytherein and a fluid inlet to the passageway, a valve for controlling theflow of fluid to said inlet and passageway, a tubu-- lar memberrotatably carried by said housing and communicating internally with saidpassageway and having external driving thread portions thereon, a secondtubular member surrounding the first tubular member and longitudinallyslidable and rotatable with respect thereto, driven portions fixedlysecured with respect to said second tubular member and engaging anddrivable by said thread portions, shiftable keying means having a keyingposition in which it is adapted to prevent unwanted rotation of saidsecond tubular member during longitudinal travel of the latter, wherebysaid second tubular member may be driven longitudinally in response torotation of said first tubular member, means supporting said keyingmeans for independent shifting movement to and from keying position,means normally holding the keying means against such shifting movementincluding a releasable latch for maintaining said keying means in saidkeying position and which, when released, permits shifting of the keyingmeans to a, non-keying position and resultantly permits rotation of saidsecond tubular member.

8. Means as set forth in claim 7, including a valve actuating elementactuatable in response to release of said keying means.

9'. Means as set forth in claim '7 wherein said keying means comprises alaterally movable bar,

valve actuating means operatively connected to the bar and movable toactuate said valve in response to lateral movement of said bar out ofthe operative keying position, means to release said latch in responseto attainment of a predetermined longitudinal position by said secondtubular member, and a combined keying and camming element secured to andmovable both longitudinally and rotatably with said second tubularmember whereby said second tubular member is rotatable withoutlongitudinal movement thereof, and whereby said bar may be movedlaterally in response to rotation of said second tubular element afterrelease of the-latch, and the valve is actuatable by such rotation.

10. Means as set forth in claim 9 wherein release of said latch permitslateral movement of said bar in one direction only, spring means urgingthe bar in the opposite direction to that in which it is movable uponrelease of said latch, said combined keying and camming elementcomprising a cam having portions adapted to extend beside said bar whenthe same is latched, and

12 having peripheral portions adapted to maintain the bar in laterallydisplaced position during at least a part of the rotation of said secondtubular member.

11. Means as set forth in claim 9 wherein saint combined keying andcamming element also carries a latch actuating portion for releasingsaid latch.

12. Means as set forth in claim 9 wherein said combined keying andcamming element also carries a latch actuating portion for releasingsaid latch, and wherein release of said latch permits lateral movementof said bar in one direction only, spring means urging the bar in theopposite direction to that in which it is movable upon release of saidlatch, said combined keying and camming element comprising a cam havingportions adapted to extend beside said bar when the same is latched, andhaving peripheral portions adapted to maintain the bar in laterallydisplaced position during at least a part of the rotation of said secondtubular member.

HARRY E. BRELSFORD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,465,387 Bowers Aug. 21, 19231,773,801 Wilson Aug. 26, 1930 1,944,324 House et al Jan. 23, 19342,104,003 Schiefier Dec. 28, 1937 2,110,534 Snow et a1. Mar. 8, 19382,249,741 Bowers et al July 22, 1941 2,303,152 Weeks Nov. 24, 19422,351,117 Glinn et a1. June 13, 1944 FOREIGN PATENTS Number Country Date305,875- Italy Feb. 18, 1933

